System and method of blade-tip facilitated aircraft capture

ABSTRACT

A method of capturing an aerial vehicle comprises rotating a first blade of the aerial vehicle, the first blade coupled to a hub of the aerial vehicle and having a contour configured to facilitate entanglement of a payload line of a winch system around the aerial vehicle. The method further comprises contacting, by a leading edge of the first blade, the payload line of the winch system and pulling the payload line towards the hub of the aerial vehicle, wherein the payload line is pulled towards the hub as the first blade continues to rotate and wherein continued rotation of the first blade causes the payload line to be tangled around the hub of the aerial vehicle.

RELATED APPLICATION

This application is a continuation-in-part of pending U.S. patentapplication Ser. No. 15/444,649 entitled “Airborne Payload ControlSystem,” which was filed on Feb. 28, 2017.

TECHNICAL FIELD

This disclosure relates in general to aircraft capture of aircraft andmore particularly to a system and method of blade-tip facilitatedaircraft capture.

BACKGROUND

The ability for a moving aircraft to control the position of a payloadin space may enable a variety of missions. As an example, such anability would enable a moving aircraft to recover a mobile payload suchas an aerial vehicle. It may be desirable to recover or otherwiseretrieve a mobile aerial vehicle in the event that the aerial vehicledoes not have the power or battery life to travel to its finaldestination.

SUMMARY OF THE DISCLOSURE

According to one embodiment, a method of capturing an aerial vehiclecomprises rotating a first blade of the aerial vehicle, the first bladecoupled to a hub of the aerial vehicle and having a contour configuredto facilitate entanglement of a payload line of a winch system aroundthe aerial vehicle. The method further comprises contacting, by aleading edge of the first blade, the payload line of the winch systemand pulling the payload line towards the hub of the aerial vehicle,wherein the payload line is pulled towards the hub as the first bladecontinues to rotate and wherein continued rotation of the first bladecauses the payload line to be tangled around the hub of the aerialvehicle.

Technical advantages of certain embodiments may include capturing andretrieving an airborne aerial vehicle. Additionally, certain embodimentsmay provide controlled retrieval of a mobile payload. Other technicaladvantages will be readily apparent to one skilled in the art from thefollowing figures, descriptions, and claims. Moreover, while specificadvantages have been enumerated above, various embodiments may includeall, some, or none of the enumerated advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description, taken inconjunction with the accompanying drawings, in which:

FIG. 1 illustrates an airborne payload control system, according tocertain embodiments;

FIG. 2 illustrates a perspective view of an example winch system of theairborne payload control system of FIG. 1, according to certainembodiments;

FIG. 3 illustrates a rear view of the example winch system of FIG. 2;

FIG. 4 illustrates a method of operation for the airborne payloadcontrol system of FIG. 1, according to one embodiment;

FIG. 5 illustrates a method of operation for the winch system of FIG. 2,according to one embodiment;

FIGS. 6A-6D illustrate examples of blade contours that may facilitateentanglement and capture of an aircraft by the winch system of FIG. 2,according to certain embodiments;

FIGS. 7A-7E illustrate an example of a time progression of blade-tipfacilitated capture of an aircraft by the winch system FIG. 2, accordingto one embodiment;

FIG. 8 illustrates a method of operation for blade-tip facilitatedcapture of an aircraft, according to one embodiment;

FIG. 9 illustrates an example computer system that may be included in acontroller of the airborne payload control system of FIG. 1, accordingto certain embodiments.

DETAILED DESCRIPTION OF THE DISCLOSURE

To facilitate a better understanding of the present disclosure, thefollowing examples of certain embodiments are given. The followingexamples are not to be read to limit or define the scope of thedisclosure. Embodiments of the present disclosure and its advantages arebest understood by referring to FIGS. 1 through 9, where like numbersare used to indicate like and corresponding parts.

This disclosure recognizes using an integrated systems approach topayload release and retrieval. Such approach may permit fixed-wingaircraft to exert helicopter-like control over a payload line. Theapproach may also permit autonomous unmanned aircraft to hold a payloadstationary during flight. Integrating multiple systems for payloadrelease and retrieval as described herein may permit the airbornepayload control system to stabilize and control the end of a payloadline in both position and altitude.

FIG. 1 illustrates an airborne payload control system 100 operable tomaintain the position and altitude of the end of a payload line.Airborne payload control system 100 may, in some embodiments, include anaircraft 110, a winch system 120, a payload line 130, a line sensor 140,and one or more controllers 150. One or more components of airbornepayload control system 100 may be communicably coupled to ensure controlover payload line 130, which may then be used to release, retrieve,and/or transport payload 160.

Aircraft 110 may be any vehicle operable to fly in the air. In someembodiments, aircraft 110 is an unmanned aerial vehicle (“UAV”) thatdoes not require manned operation of aircraft 110. Aircraft 110 may alsobe any fixed-wing aircraft such as an airplane. This disclosurerecognizes that aircraft 110 may, in some embodiments, transport payload160. In some embodiments, payload 160 is transported within a fuselageof aircraft 110. In other embodiments, payload 160 may be transportedvia payload line 130. As an example, payload 160 may be coupled to anend of payload line 130 and may be reeled into or out of aircraft 110.

Aircraft 110 may include an onboard avionics system. In someembodiments, features of the onboard avionic system may be controlled byone or more controllers (e.g., controller 150 of FIG. 1). For example,in response to receiving instructions from controller 150, the onboardavionic system may adjust or maintain one or more of the flight path,speed, orbit, and/or altitude of aircraft 110. In some embodiments,controller 150 instructs the onboard avionics system to adjust ormaintain one or more of the flight path, speed, orbit, and/or altitudeof aircraft 110 in order to control a position and/or altitude of theend of payload line 130. By controlling the position and/or altitude ofthe end of payload line 130, the position and/or altitude of payload 160may be controlled.

Maintaining control over payload 160 may enable various missions such asthe controlled retrieval of a stationary or mobile payload. As anotherexample, maintaining control over payload 160 may enable controlledrelease of payloads (e.g., careful placement of fragile payloads on theground). As yet another example, maintaining control over payload 160may enable inconspicuous data retrieval (e.g., holding a payload such asa sensor or camera above the ground while the aircraft flies at analtitude that is visually and acoustically undetectable).

As described above, airborne payload control system 100 may also includewinch system 120 and payload line 130. Winch system 120 may, in someembodiments, be located aboard aircraft 110 (e.g., in fuselage ofaircraft 110). In other embodiments, winch system 120 is coupled to anexterior wall of aircraft 110. For example, as depicted in FIG. 1, winchsystem 120 is coupled to the underside of aircraft 110. Winch system 120may be operable to spool payload line 130. Accordingly, winch system 120is the component of airborne payload control system 100 that isresponsible for reeling in and reeling out payload line 130. In someembodiments, a first end 130 a of payload line 130 is coupled to winchsystem 120 and a second end 130 b of payload line 130 is not coupled towinch system 120. As an example, first end 130 a of payload line 130 maybe secured to main reel 210 and second end 130 b of payload line 130 mayinitially be wound about main reel 210 and thereafter be reeled towardsor away from aircraft 110. Additional details of winch system 120 aredescribed below in reference to FIG. 2.

Second end 130 b of payload line 130 may be operable to couple topayload 160. In some embodiments, payload 160 is coupled to second end130 b of payload line 130 using a coupling mechanism (not depicted). Insome embodiments, coupling mechanism is a magnet, a hook, or a suctioncup. Although this disclosure describes particular types of couplingmechanisms, this disclosure recognizes any suitable coupling mechanismoperable to couple payload 160. In other embodiments, payload 160 iscoupled to second end 130 b of payload line 130 without the aid of anadditional component. As an example, second end 130 b of payload line130 may be configured to couple to a moving payload 160 such as theweight-shifting coaxial helicopter described in U.S. application Ser.No. 15/085,540 and incorporated by reference herein. In such an example,the weight-shifting coaxial helicopter may fly into or near the secondend 130 b of payload line 130, causing payload line 130 to get tangledon or between the blades of weight-shifting coaxial helicopter. As aresult, the weight-shifting coaxial helicopter is secured or otherwisecoupled to second end 130 b of payload line 130. The capture andretrieval of aircraft will be described in more detail below inreference to FIGS. 6-8.

Payload line 130 may comprise any suitable material. For example,payload line 130 may comprise monofilament or braided, synthetic ornon-synthetic rope, string, twine, or fishing line. Preferably, payloadline 130 comprises a material that has the desired tensile strength,diameter, drag, and shape memory.

Airborne payload control system 100 may also include line sensor 140 asdescribed above. In some embodiments, line sensor 140 is positioned onpayload line 130. Line sensor 140 may be operable to detect informationabout payload line 130. For example, line sensor 140 may be operable todetect information about one or more of a position of the payload line(e.g., a position in space of second end 130 b of payload line 130), avelocity of the payload line (e.g., a velocity of second end 130 b ofpayload line 130), and an altitude of second end 130 b of payload line130. Although this disclosure describes certain types of informationthat may be detected by line sensor 140, this disclosure recognizes thatline sensor 140 may detect any suitable information. As used herein,suitable information that may be detected by line sensor 140 includesany information that may be utilized by one or more controllers 150 ofairborne payload system 150. In some embodiments, the informationdetected by line sensor 140 is relayed to other components of airbornepayload control system 100 (e.g., via RF signal). As an example, theinformation detected by line sensor 140 may be sent to one or morecontrollers 150 of airborne payload control system 100. In someembodiments, controllers 150 may provide instructions to aircraft 110and/or winch system 120 based on the information detected by line sensor140. For example, in response to line sensor 140 detecting that thevelocity of second end 130 b of payload line 130 is increasing in adownward direction, one or more controllers 150 of airborne payloadsystem 100 may instruct winch system 120 to reel in payload line 130 ata rate of speed to correct the downward motion. As another example, inresponse to line sensor 140 detecting that the altitude of second line130 b of payload line 130 is decreasing, one or more controllers 150 ofairborne payload system 100 may instruct aircraft 110 to increase thealtitude of aircraft 110 to maintain the desired altitude of second end130 b of payload line 130.

Line sensor 140 may detect information about payload line 130continuously or periodically. For example, line sensor 140 maycontinuously detect information about payload line 130 and make suchreal-time information available to one or more components of airbornepayload control system 100. As another example, line sensor 140 maydetect information about payload line 130 periodically (e.g., every onesecond). In a preferred embodiment, line sensor 140 detects and relaysreal-time information. This disclosure recognizes that control overpayload line 130 and/or payload 160 is more precise when real-timeinformation is detected as compared to using periodic information.

In some embodiments, line sensor 140 is under the direction and/orcontrol of controller 150. For example, controller 150 may control theoperation of line sensor 140. In such an embodiment, controller 150 mayinstruct line sensor 140 when to begin detecting information aboutpayload line 130. As an example, controller 150 may instruct line sensor140 to begin detecting information about payload line 130 when payload160 is a particular distance from aircraft 110. Controller 150 may alsoinstruct line sensor when, or with what component, to share the detectedinformation. As an example, controller 150 may instruct line sensor 140to continuously share real-time information with a data link associatedwith winch system 120.

Airborne payload control system 100 may also include one or morecontrollers 150 as described above. As illustrated in FIG. 1, airbornepayload control system 100 includes a single controller 150. Thisdisclosure recognizes that one or more components of airborne payloadcontrol system 100 may include a controller 150. As an example, aircraft110 may be associated with a first controller 150 and winch system 120may be associated with a second controller 150. In such an example, thefirst controller 150 and the second controller 150 may be configured toreceive data from one or more other components of airborne payloadcontrol system 100. For example, the first controller 150 and the secondcontroller 150 may receive information about payload line 130 from linesensor 140 and may receive information about payload 160 from trackingand control system 170. In some embodiments, the one or more controllers150 may be configured to exchange information with one another (e.g.,the first controller relays information about the aircraft's position,flight path, speed, orbit, and altitude to the second controller). Inother embodiments, aircraft 110 and/or winch system 120 may beassociated with a data link which is configured to share data with theone or more controllers 150.

In some embodiments, controller 150 includes or is a computer systemsuch as computer system 600 described below in reference to FIG. 9.Controller 150 may be operable to receive information from one or moreof line sensor 140 and tracking and control system 170 and provideoperation instructions to one or more of aircraft 110 and winch system120. In some embodiments, the one or more controllers 150 are configuredto analyze the received information and compute various factors that maystabilize the second end 130 b of payload line 130. For example,controllers 150 may compute factors such as optimal headings, flightpaths, flight speeds, reel speeds, reel directions, payload linelengths, and payload line tensions. In some embodiments, the logic usedto compute such factors is stored in a memory of controller 150 (e.g.,memory 920 of FIG. 9).

Airborne payload control system 100 may also include other componentssuch as a tracking and control system 170 for payload 160. The trackingand control system 170 of payload 160 may be configured to senseinformation about the position or location of payload 160 and relay thesensed information to other components of airborne payload controlsystem 100. As an example, tracking and control system 170 may sendinformation about the location and position of payload 160 tocontrollers 150 of airborne payload control system 100. Airborne payloadcontrol system 100 may in turn use this information to instruct aircraft110 and/or winch system 120. Although this disclosure describes anddepicts airborne payload control system 100 including certaincomponents, airborne payload control system 100 may include any suitablecomponents. For example, this disclosure recognizes that airbornepayload control system 100 may include components and features that maybe used in conjunction with tracking, control, and transport ofpayloads.

In operation, winch system 120, under direction from controller 150, mayreel payload line 130 out in anticipation of retrieving or releasingpayload 160. As an example, winch system 120 may begin reeling outpayload line 130 in response to receiving an instruction from controller150 to increase the length of payload line 150 by 300 feet. In someembodiments, controller 150 sends such instruction to winch system 120after determining that a payload 160 requiring pick-up is one mile away.This determination may be based on information received from trackingand control system 170 of payload 160. After winch system 120 reels outpayload line 130 in accordance with the instructions from controller150, controller 150 may begin receiving data from line sensor 140 aboutpayload line 130. As an example, controller 150 may receive thefollowing information from line sensor: 3D velocity components (e.g.,Vnorth, Veast, Vdown) and 3D position components (e.g., latitude,longitude, altitude). In addition receiving information from line sensor140, controller 150 may also receive, or continue to receive,information from tracking and control system 170 of payload 170. Forexample, controller 150 may receive the following information fromtracking and control system 170: 3D velocity components (e.g., Vnorth,Veast, Vdown) and 3D position components (e.g., latitude, longitude,altitude). Controller 150 may use the received information to provideoperation instructions to one or more of aircraft 110 and winch system120. As an example, based on the information received by controller 150,controller 150 may instruct winch system to adjust the length of payloadline 130. As another example, controller 150 may instruct aircraft 110to adjust the flight path of aircraft 110. In some embodiments,controller 150 facilitates the operation of aircraft 110 by providinginstructions to the onboard avionics system. In some embodiments,controller 150 facilitates the operation of winch system 120 byproviding instructions to one or more components of winch system 120(e.g., first motor 220, second motor 240, etc.). Controller 150 may usethe real-time information received from one or more of line sensor 140and tracking and control system 170 to compute various factors such asoptimal headings, flight paths, flight speeds, reel speeds, reeldirections, payload line lengths, and payload line tension. Controller170 may then instruct one or more of aircraft 110 and winch system 120to make operational adjustments based on the computations. For example,controller 150 may instruct aircraft 110 to change its flight path basedon computations. As another example, controller 150 may instruct winchsystem 120 to increase tension on payload line 130 based on thecomputations. In some embodiments, implementing the instructions ofcontroller 150 stabilizes the second end 130 a of payload line 130. Forexample, implementing the instructions of controller 150 may permit thesecond end 130 a of payload line 130 to maintain a particular altitude(e.g., 1000 feet MSL) and a particular position (e.g., Latitude 35.3degrees north, Longitude 120.8 degrees west) as aircraft 110 continuesto fly through the air.

Turning now to FIG. 2, winch system 120 may comprise a main reel 210, afirst motor 220, a set of pinch rollers 230 (i.e., 230 a-b), and asecond motor 240. As described above, winch system 120 is the componentresponsible for reeling payload line 130 in and out. As used herein,reeling payload line 130 out refers to increasing the length of payloadline 130 extending from aircraft 110, and reeling payload line 130 inrefers to decreasing the length of payload line 130 extending fromaircraft 110. Main reel 210 may be a spool about which payload line 130is wound. As described above, payload line 130 may be coupled to mainreel 210 at a first end 130 a and all or a portion of payload line 130may be wound about main reel 210. Second end 130 b of payload line 130may be configured to be spooled onto and off of main reel 210. This isbest illustrated in FIG. 3 wherein payload line 130 is wound about mainreel 110 and second end 130 b of payload line 130 is threaded through anaperture 330 in shaft 320.

In some embodiments, payload line 130 is spooled onto and off of mainreel 210 by turning main reel 210. For example, turning main reel 210 ina first direction may feed payload line 130 out and turning main reel210 in a second direction may reel payload line 130 in. In someembodiments, first motor 220 is operable to turn main reel 210 in boththe first and the second direction. First motor 220 may receiveinstructions to turn main reel 210 from one or more controllers ofairborne payload control system 100. As an example, controller 150 ofFIG. 1 may send instructions to first motor 220 to turn main reel 210 inthe first direction and, in response, first motor 220 may turn main reel210 in the first direction.

As described above, winch system 120 may include pinch rollers 230. Insome embodiments, payload line 130 may be threaded between first pinchroller 230 a and second pinch roller 230 b. Pinch rollers 230 may beconfigured to maintain tension on payload line 130. In some embodiments,tension on payload line 130 is maintained by keeping payload line taughtbetween main reel 210 and pinch rollers 230. This may be achieved byturning pinch rollers 230 in the first and/or second direction. In someembodiments, one or more pinch rollers 230 are rotated by second motor240.

Second motor 240 may be configured to turn one or more pinch rollers230. For example, second motor 240 may be configured to turn first pinchroller 230 a but not second pinch roller 230 b. Second motor 240 may beconfigured to turn one or more pinch rollers 230 in the first directionand/or the second direction. In some embodiments, second motor 240receives instructions from one or more controllers of airborne payloadcontrol system 100. For example, controller 150 of FIG. 1 may sendinstructions to second motor 240 to turn first pinch roller 230 a in thefirst direction and, in response, second motor 240 may turn first pinchroller 230 a in the first direction.

In some embodiments, one or more controllers of airborne payload controlsystem 100 may send instructions to one or more of first motor 220 andsecond motor 240. For example, in response to determining to feedpayload line 130 out, controller 150 of FIG. 1 may instruct second motor240 to turn one or more pinch rollers 230 in the first direction (tofeed payload line 130 out). As another example, in response todetermining to feed payload line 130 in, controller 150 of FIG. 1 mayinstruct first motor 230 to turn main reel 210 in the second direction(to reel payload line 130 in). In addition to instructing motors 220 and240 regarding directions of turning, controller(s) 150 may instructmotors 220 and 240 to turn main reel 210 and pinch rollers 230,respectively, at particular rates. In some embodiments, suchinstructions may enable controller 150 to control the speed and/orlength of payload line 130 and/or tension on payload line 130.

Controller(s) 150 may send instructions to first motor 220 and secondmotor 240 that enable main reel 210 and pinch rollers 230 to cooperateto feed payload line 130 in and out. For example, in response todetermining to feed payload line 130 in, controller 150 of FIG. 1 mayinstruct first motor 230 to turn main reel 210 in the second directionand instruct second motor 220 to apply a braking function. As anotherexample, in response to determining to feed payload line 130 out,controller 150 of FIG. 1 may instruct second motor 240 to turn one ormore pinch rollers 230 in the second direction and instruct first motor220 to apply a braking function. Such instructions may permit payloadline 130 to be reeled in and out while also keeping payload line 130taught between main reel 210 and pinch roller 230 thus preventingpayload line 130 from tangling (e.g., as may occur when reeling inpayload line 130 at high speeds and not keeping payload line 130taught). In some embodiments, the instructions of controller(s) 150 tofirst motor 220 and/or second motor 240 may permit winch system 120 tomaintain second end 130 b of payload line 130 in a particular position(e.g., latitude, longitude, and altitude).

Each of motors 220 and 240 may be associated with one or more opticalencoders (not illustrated). The one or more optical encoders may beconfigured to detect information about payload line 130 and relay theinformation to one or more controllers of airborne payload controlsystem 100 (e.g., controller 150). As an example, the informationdetected by an optical encoder may be used to determine the length ofpayload line 130 on main reel 210. Such information may in turn be usedby controller 150 to provide instructions to one or more components ofairborne payload control system 100 (e.g., first motor 220, second motor240, etc.). For example, in response to determining, based oninformation from an optical encoder associated with first motor 220,that payload line 130 on main reel 210 is nearly empty, controller 150sends instructions to reduce the speed of second motor 240 while reelingout payload line 130.

As described above, instructions from controller(s) 150 may be based oninformation received from line sensor 140. For example, in response toreceiving information from line sensor 140, controller 150 may sendinstructions to one or more of first motor 220 and second motor 240. Inthis manner, controller(s) 150 may use feedback from line sensor 140 tocontrol the distance, velocity, acceleration, and/or jerk on payloadline 130. In some embodiments, the distance, velocity, acceleration,and/or jerk of payload line 130 is controlled to maintain a particularposition (e.g., latitude, longitude, and altitude) of second end 130 bof payload line 130 during the flight of aircraft 110.

In some embodiments, winch system 120 includes additional components.For example, as illustrated in FIG. 2, winch system 120 includes amounting plate 250. Mounting plate 250 may be configured to mount winchsystem 120 to aircraft 110. In some embodiments, mounting plate 250includes apertures 252 configured to receive fasteners therethrough.Fasteners may be used to couple winch system 120 to aircraft 110. Winchsystem 120 may also include an eye 260. In some embodiments, eye 260 isa plate comprising an aperture through which second end 130 b of payloadline 130 is threaded. Eye 260 may be configured to restrict movement ofpayload line 130. This may be desirable to limit movement of payloadline 130 as it is reeled in and out by winch system 120.

Winch system 120 may also include one or more servo motors (e.g., servomotors 270 and 310) that provide additional functionality. Servo motors270 and 310 and the functionality they provide are best illustrated inFIG. 3. Servo motor 270 may be operable to move a locking bar 272 from afirst position to a second position. In some embodiments, main reel 210may be turned in the first or the second direction when locking bar 272is in the first position (unlocked position) and main reel 210 may beprevented from turning when locking bar 272 is in the second position(locked position). In some embodiments, servo motor 270 is configured toreceive instructions from one or more controllers of airborne payloadcontrol system 100 (e.g., controller 150 of FIG. 1) and move locking bar272 from the first position to the second position (or from the secondposition to the first position) upon receiving instructions to do so. Asan example, upon receiving instructions from controller 150 to movelocking bar 272 into the second position, servo motor 170 may pushlocking bar 272 into main reel 210, thereby preventing main reel 210from turning.

FIG. 3 also illustrates servo motor 310. Servo motor 310 may be operableto move shaft 320. As an example, servo motor 310 may be operable tomove shaft 320 from a first position to a second position. As describedabove, shaft 320 may include aperture 330 through which second end 130 bof payload line 130 is threaded. In some embodiments, moving shaft 320from the first position to the second position causes payload line 130to be distributed in a substantially even manner on main reel 210. Asused herein, distributing payload line 130 in a “substantially evenmanner” prevents payload line 130 from being lumped on the sides or inthe center of main reel 210. This disclosure recognizes certain benefitsof distributing payload line 130 in a substantially even manner acrossmain reel 210. For example, such distribution may reduce the likelihoodof tangles, catches, and/or snags. Although this disclosure describesand depicts winch system 120 comprising particular components, thisdisclosure recognizes that winch system 120 may comprise any suitablecomponent.

This disclosure also contemplates a line cutting feature of winch system120. In some embodiments, this line cutting feature is performed usingcomponents described herein. Such feature may be performed at thedirection of controller(s) 150. For example, controller 150 may instructservo motor 170 to move locking bar 272 into the locked position and,after locking bar 272 is positioned in the locked position, instructsecond motor 240 to begin feeding line out, thus causing a friction cutof payload line 130.

FIG. 4 illustrates a method 400 of operation for airborne payloadcontrol system 100. Method 400 may be performed by one or morecontrollers of airborne payload control system 100. As an example,controller 150 of FIG. 1 may perform method 400. As described above, acontroller operable to perform method 400 may be a computer such ascomputer 900 of FIG. 9. Method 400 may be stored in a memory ofcontroller (e.g., memory 920 of FIG. 9).

Method 400 may begin in step 405 and proceed to step 410. At step 410,controller 150 may receive information about payload line 130. Asdescribed above, controller 150 may receive information about payloadline 130 from line sensor 140. The information received by controller150 may comprise one or more of: a position of payload line 130; avelocity of payload line 130; and an altitude of second end 130 b of thepayload line 130. Although this disclosure recognizes particular typesof information that may be sensed by line sensor 140, this disclosurerecognizes that line sensor 140 may detect any suitable information(e.g., information that would be helpful in maintaining a position ofsecond end 130 b of payload line 130). In some embodiments, afterreceiving information about payload line 130, method 400 proceeds tostep 420.

At step 420, controller 150 provides instructions to aircraft 110 andwinch system 120 based on information received at step 410. In someembodiments, the instructions provided by controller 150 at step 420cause a position of second end 130 b of payload line 130 to bemaintained. As described above, controller 150 may provide instructionsto an onboard avionic system operable to control one or more of theflight path, speed, orbit, and/or altitude of aircraft 110. Controller150 may also provide instructions to one or more of first motor 220and/or second motor 240. As described above, instructions to first motor220 may include instructions regarding one or more of a direction ofturning main reel 210, a speed at which to turn main reel 210, a tensionon payload line 130, and an application of a braking functionality.Instructions to second motor 220 may include instructions regarding oneor more of a direction of turning one or more pinch rollers 130, a speedof turning one or more pinch rollers 130, a tension on payload line 130,and an application of a braking functionality. Controller 150 may alsoprovide instructions to one or more servo motors of winch system 120.For example, controller 150 may instruct servo motor 270 to move lockingbar 272 from a first position to a second position. As another example,controller 150 may instruct servo motor 310 to move shaft 320 from afirst position to a second position. In some embodiments, afterperforming step 420, method 400 proceeds to an end step 425.

FIG. 5 illustrates a method 500 of operation for winch system 120.Method 500 may be performed by one or more controllers of airbornepayload control system 100. As an example, controller 150 of FIG. 1 mayperform method 500. As described above, a controller operable to performmethod 500 may be a computer such as computer 900 of FIG. 9. Method 500may be stored in a memory of controller (e.g., memory 920 of FIG. 9).

Method 500 may begin in step 505 and proceed to step 510. At step 510,one or more of first motor 220 and second motor 240 receivesinstructions to spool payload line 130. In some embodiments, thereceived instructions instruct first motor 220 and/or second motor 240to spool payload line 130 in or out. As described above, payload line130 may be spooled out by turning one or more of main reel 210 and/orpinch rollers 130 in the first direction and payload line 130 may bespooled in by turning one or more of main reel 210 and/or pinch rollers130 in the second direction.

In some embodiments, payload line 130 is spooled out by instructingfirst motor 220 to perform a braking function and instructing secondmotor 240 to turn in the first direction. In some other embodiments,payload line 130 is spooled in by instructing first motor 220 to turn inthe second direction and instructing second motor 240 to apply a brakingfunction. In some embodiments, the received instructions instruct firstmotor 220 and/or second motor 240 to operate at a particular speed. Inother embodiments, the received instructions instruct first motor 220and/or second motor 240 to pull payload line 130 taught. Although thisdisclosure describes particular types of instructions that may bereceived from one or more controllers of airborne payload control system100, this disclosure recognizes that the received instructions mayinclude any suitable information that may enable winch system 120 tocontrol the position of second end 130 b of payload line 130. In someembodiments, after first motor 220 and/or second motor 240 receivesinstructions to spool payload line 130, the method 500 proceeds to step520.

At step 520, first motor 220 and/or second motor 240 operate based onthe instructions received at step 510. For example, first motor 220 mayapply a braking function in response to receiving an instruction toperform a braking function. As another example, second motor 240 maybegin turning pinch roller 230 a at a particular rate (e.g., 150 rpm) inthe first direction in order to increase the length of payload line 130.The instructions may be implemented serially or simultaneously. In someembodiments, implementing the instructions received at step 510 causethe position of second end 130 b of payload line 130 (e.g., latitude,longitude, and altitude) to be maintained.

The descriptions below of FIGS. 6-8 generally describe the capture andretrieval of aircraft and aerial vehicles. In some embodiments, theaircraft and/or aerial vehicles are captured and retrieved by airbornepayload control system 100. Generally, FIGS. 6A-6D illustrate differentembodiments of blades 605 configured to facilitate aircraft capture,FIGS. 7A-7E illustrate an example time progression of capturing anaircraft using blade-tip facilitated capture, and FIG. 8 illustrates anembodiment of a method of operation for blade-tip facilitated capture ofan aircraft.

Turning first to FIGS. 6A-6D, different embodiments of blades 605 aredepicted. Each of FIGS. 6A-6D illustrate a different embodiment of blade605, each blade 605 having a different contour. As used herein, acontour of a blade 605 refers to the outline or shape of blade 605.Additionally, blades 605 may include one or more leading edges 615 a andtrailing edges 615 b. As used herein, a leading edge 615 a may refer toan edge of blade 605 that is configured to contact payload line 130before the trailing edge 615 b. As depicted in FIGS. 6A-6D, each blade605 includes two leading edges 615 a and two trailing edges 615 b,wherein the distal portions of blade 605 include leading edges 615 a andthe proximal portions of blade 605 (portions of blade 605 nearest hub610) include trailing edges 615 b.

In some embodiments, the contour of blade 605 defines one or morefeatures 620 that may be configured to hook payload line 130. Feature620 may be a protrusion 620 a in some embodiments. In other embodiments,feature 620 may be an indention 620 b. As used herein, a protrusion 620a may refer to a first portion of blade 605 that projects outwardrelative to a second portion of blade 605 (e.g., portion of blade 605that includes trailing edge 615 b) and an indention 620 b may refer to afirst portion of blade 605 that recesses inwardly relative to the secondportion of blade 605. In some embodiments, blades 605 couple to a hub610 of aerial vehicle.

In some embodiments, feature 620 is located at or near the leading edge615 a of blade 605. In some embodiments, blade 605 includes only asingle type of feature 620 (e.g., blade 605 of FIGS. 6C-6D). In otherembodiments, blade 605 has more than one type of feature 605 (e.g.,blade 605 of FIGS. 6A-6B). Blade 605 may include one or more features620. For example, blade 605 of FIGS. 6A and 6B include four features620: two protrusions 620 a (a protrusion 620 a on each distal portion ofblade 605) and two indentions 620 b (an indention 620 b on each proximalportion of blade 605). As another example, blade 605 of FIGS. 6C and 6Dinclude two features 620: blade 605 of FIG. 6C includes two protrusions620 a and blade 605 of FIG. 6D includes two indentions 620 b.

In some embodiments, blade 605 is coupled to a hub 610 of an aerialvehicle. As used herein, hub 610 refers to a central part of the aerialvehicle from which one or more blades 205 radiate. As depicted in FIGS.6A-6D, each blade 205 coupled to hub 610 is a single continuouscomponent. This disclosure also recognizes that each blade 205 depictedin FIGS. 6A-6D may be two or more separate components. For example, thisdisclosure recognizes that blade 605 of FIG. 6A may be divided into twohalves (e.g., blade 605 a and 605 b (not depicted)) and each half maycouple to hub 610. In such an embodiment, one end of blade 605 mayinclude a leading edge 615 a and the other end of blade 605 may includea trailing edge 615 b. Additionally, in such an embodiment, blade 605may include one or more features 620 (e.g., a protrusion 620 a and/or anindention 620 b). In some embodiments, features 620 are located at ornear leading edge 615 a.

Features 620 may be formed from rounded edges or angles (e.g.,protrusions 620 a and indentions 620 b of FIGS. 6A and 6B) in someembodiments. In other embodiments, features 620 may be formed fromstraight edges or angles (e.g., protrusions 620 a and indentions 620 bof FIGS. 6C and 6D). Although this disclosure describes and depictsspecific types of features 620 and specific contours that form features620, this disclosure recognizes blades 605 may include any suitablefeature 620 formed from any suitable contour.

Additionally, this disclosure recognizes that blade 605 may be aseparate component that can couple to a pre-existing wing of an aerialvehicle. For example, blade 605 may be a component configured to snap onor over one or more pre-existing wings of an off-the-shelf quadcopter orother aerial vehicle. In such an example, blade 605 may provide anoff-the-shelf aerial vehicle with blades having a contour permittingblade-tip facilitated retrieval.

Turning now to FIGS. 7A-7E, these figures illustrate an example ofstages or phases that may occur when capturing an aerial vehicle usingblade-tip facilitated capture. FIGS. 7A-7D illustrate a top view of anaerial vehicle approaching and interacting with payload line 130 whileFIG. 7E illustrates a side view of the aerial vehicle entangled bypayload line 130.

FIG. 7A illustrates an aerial vehicle having blades 605 and hub 610. Asillustrated in FIG. 7A, the aerial vehicle has two blades: first blade605 a and second blade 605 b. In some embodiments, first blade 605 a maybe positioned superior to (in space) second blade 605 b such that blades605 a-b cannot collide with each other when they are being rotated. Inembodiments with more than one blade 605, blades 605 may becounter-rotating (rotating in opposite directions) such as described inreference to the weight-shifting coaxial helicopter of U.S. applicationSer. No. 15/085,540. As depicted in FIG. 7A, blade 605 a rotates in afirst direction while blade 605 b rotates in a second direction. Inother embodiments with more than one blade 605, blades 605 may beco-rotating (rotating in the same direction). Although this disclosuredescribes and depicts an embodiment of an aerial vehicle having twoblades 605, this disclosure recognizes that an aerial vehicle to becaptured may include any suitable number of blades 605 (e.g., one,three, four, six). In some embodiments, blades 605 are fixed-pitchblades. In other embodiments, blades 605 are collective-pitch blades.

In FIG. 7A, one or more of counter-rotating blades 605 approach, orotherwise come within reach of, payload line 130. As depicted in FIGS.7A-7E, blades 605 have a contour that is configured to facilitateentanglement of the aerial vehicle in payload line 130. Notably, inFIGS. 7A-7E, blades 605 include a protrusion feature 620 a on theleading edge 615 a of blades 605. FIG. 7B illustrates a phase at whichprotrusion feature 620 a of blade 605 a configured to hook payload line130. In some embodiments, protrusion feature 620 a of blade 605 aprevents payload line from sliding off the distal end of blade 605 a dueto the contour of leading edge 615 a. FIGS. 7C and 7 d illustrate phasesat which payload line 130 traverses along blade 605 a, from leading edge615 a to trailing edge 615 b, towards hub 610. In some embodiments,payload line 130 moves along blade 605 towards trailing edge 615 b asblade 605 continues to rotate.

Rotating blade 605 may cause payload line 130 to wrap around hub 610 asdepicted in FIG. 7E. Continued wrapping of payload line 130 around hub610 may result in entanglement of payload line 130 around hub 610.Entanglement may occur after the pulling-in force on payload line 130exceeds the tension force on payload line 130. In some embodiments,payload line 130 wraps around hub 610 between first blade 605 a andsecond blade 605 b. This disclosure recognizes that entangling aroundthis portion of the aerial vehicle may prevent damage to payload line130 and/or motors and/or shaft of the aerial vehicle. The aerial vehiclemay be captured whenever payload line 130 is sufficiently wrapped aroundaerial vehicle such that the aerial vehicle can be reeled in by winchsystem 120.

Although not depicted, this disclosure also recognizes that second blade605 b may also hook payload line 130 and cause payload line 130 to wraparound hub 610 of the aerial vehicle. Accordingly, this disclosurerecognizes that second blade 605 b may be operated in a way thatfacilitates cooperation with first blade 605 a to entangle payload line130 around hub 610. This disclosure also recognizes that one or morefeatures 620 of one or more blades 605 may hook payload line 130. Insuch scenario, payload line 130 may move across the one or more blades605 from leading edge 615 a to trailing edge 615 b towards hub 610,before payload line 130 becomes entangled around hub 610.

This disclosure also recognizes that blade-facilitated capture may beperformed by an aerial vehicle having only a single blade 605. In suchembodiment, feature 620 of blade 605 may hook payload line 130 and drawpayload line 130 towards hub 610 across blade 605. The continuedrotation of blade 605 may cause payload line 130 to wrap around hub 610of the aerial vehicle. Because it may be more difficult to cause payloadline 130 to wrap around hub 610 with only one blade 605, this disclosurerecognizes that the blade rotation speed of an aerial vehicle having asingle blade 605 may be greater than the blade rotation speed of anaerial vehicle having more than one blade 605.

FIG. 8 illustrates a method 800 of capturing an aerial vehicle usingblade-tip facilitated capture. One or more steps of method 800 may beperformed by a controller of the aerial vehicle. A controller operableto perform one or more steps of method 800 may be a computer such ascomputer 900 of FIG. 9. Method 800 may be stored in a memory ofcontroller (e.g., memory 920 of FIG. 9).

Method 800 may begin at step 805 and continue to step 810. At step 810,aerial vehicle may rotate a first blade (e.g., 605 a) of the aerialvehicle. In some embodiments, a controller of the aerial vehicle causesfirst blade 605 a to rotate (e.g., by sending instructions to a motorcoupled to a rotor, which in turn may be coupled to first blade 605 a).First blade 605 a may be coupled to hub 610 and may have a contourconfigured to facilitate entanglement of payload line 130 of winchsystem 120 around the aerial vehicle as described above in reference toFIGS. 6A-6D. In some embodiments, method 800 continues to step 820 afterrotating first blade 605 a.

At step 820, the aerial vehicle contacts payload line 130 of winchsystem 120. In some embodiments, the portion of aerial vehicle thatcontacts payload line 130 is leading edge 615 a of blade 605. Leadingedge 615 a may, in some embodiments, include one or more features 620.As described above, features 620 may be, in some embodiments,protrusions 620 a and/or indentions 620 b. In some embodiments, method800 continues to step 830.

At step 830, payload line 130 is pulled towards the hub 610 of theaerial vehicle. In some embodiments, payload line 130 is pulled towardshub 610 of the aerial vehicle due to the pulling-in force exerted onpayload line 130 by first blade 605 a due to the continued rotation offirst blade 605 a. Payload line 130 may traverse leading edge 615 a andtrailing edge 615 b while being pulled towards hub 610. In someembodiments, continued rotation of first blade 605 a causes payload line130 to become tangled around hub 610 of the aerial vehicle. Entanglementmay occur when the pulling-in force exerted on payload line 130 exceedsthe tension force on payload line 130. In some embodiments, method 800continues to an end step 835 after payload line 130 is entangled aroundhub 610.

In some embodiments, method 800 may include one or more steps. Forexample, method 800 may continue from step 830 to a retrieval step thatmay be executed by airborne payload system 100. At such step,controllers 150 may instruct winch system 120 to reel in payload line130 such that the aerial vehicle may be delivered to aircraft 110.Payload line 130 may thereafter be unwound from hub 610 in order toready the aerial vehicle for future use.

FIG. 9 illustrates an example computer system 900. Computer system 900may be utilized by airborne payload control system 100 of FIG. 1. Forexample, controller 150 of FIG. 1 may be a computer system 900. Inparticular embodiments, one or more computer systems 900 perform one ormore steps of one or more methods described or illustrated herein. Inparticular embodiments, one or more computer systems 900 providefunctionality described or illustrated herein. In particularembodiments, software running on one or more computer systems 900performs one or more steps of one or more methods described orillustrated herein or provides functionality described or illustratedherein. Particular embodiments include one or more portions of one ormore computer systems 900. Herein, reference to a computer system mayencompass a computing device, and vice versa, where appropriate.Moreover, reference to a computer system may encompass one or morecomputer systems, where appropriate.

This disclosure contemplates any suitable number of computer systems900. This disclosure contemplates computer system 900 taking anysuitable physical form. As example and not by way of limitation,computer system 900 may be an embedded computer system, a system-on-chip(SOC), a single-board computer system (SBC) (such as, for example, acomputer-on-module (COM) or system-on-module (SOM)), a desktop computersystem, a laptop or notebook computer system, an interactive kiosk, amainframe, a mesh of computer systems, a mobile telephone, a personaldigital assistant (PDA), a server, a tablet computer system, or acombination of two or more of these. Where appropriate, computer system900 may include one or more computer systems 900; be unitary ordistributed; span multiple locations; span multiple machines; spanmultiple data centers; or reside in a cloud, which may include one ormore cloud components in one or more networks. Where appropriate, one ormore computer systems 900 may perform without substantial spatial ortemporal limitation one or more steps of one or more methods describedor illustrated herein. As an example and not by way of limitation, oneor more computer systems 900 may perform in real time or in batch modeone or more steps of one or more methods described or illustratedherein. One or more computer systems 900 may perform at different timesor at different locations one or more steps of one or more methodsdescribed or illustrated herein, where appropriate.

In particular embodiments, computer system 900 includes a processor 910,memory 920, storage 930, an input/output (I/O) interface 940, acommunication interface 950, and a bus 960. Although this disclosuredescribes and illustrates a particular computer system having aparticular number of particular components in a particular arrangement,this disclosure contemplates any suitable computer system having anysuitable number of any suitable components in any suitable arrangement.

In particular embodiments, processor 910 includes hardware for executinginstructions, such as those making up a computer program. As an exampleand not by way of limitation, to execute instructions, processor 910 mayretrieve (or fetch) the instructions from an internal register, aninternal cache, memory 920, or storage 930; decode and execute them; andthen write one or more results to an internal register, an internalcache, memory 920, or storage 930. In particular embodiments, processor910 may include one or more internal caches for data, instructions, oraddresses. This disclosure contemplates processor 910 including anysuitable number of any suitable internal caches, where appropriate. Asan example and not by way of limitation, processor 910 may include oneor more instruction caches, one or more data caches, and one or moretranslation lookaside buffers (TLBs). Instructions in the instructioncaches may be copies of instructions in memory 920 or storage 930, andthe instruction caches may speed up retrieval of those instructions byprocessor 910. Data in the data caches may be copies of data in memory920 or storage 930 for instructions executing at processor 910 tooperate on; the results of previous instructions executed at processor910 for access by subsequent instructions executing at processor 910 orfor writing to memory 920 or storage 930; or other suitable data. Thedata caches may speed up read or write operations by processor 910. TheTLBs may speed up virtual-address translation for processor 910. Inparticular embodiments, processor 910 may include one or more internalregisters for data, instructions, or addresses. This disclosurecontemplates processor 910 including any suitable number of any suitableinternal registers, where appropriate. Where appropriate, processor 910may include one or more arithmetic logic units (ALUs); be a multi-coreprocessor; or include one or more processors 910. Although thisdisclosure describes and illustrates a particular processor, thisdisclosure contemplates any suitable processor.

In particular embodiments, memory 920 includes main memory for storinginstructions for processor 910 to execute or data for processor 910 tooperate on. As an example and not by way of limitation, computer system900 may load instructions from storage 930 or another source (such as,for example, another computer system 900) to memory 920. Processor 910may then load the instructions from memory 920 to an internal registeror internal cache. To execute the instructions, processor 910 mayretrieve the instructions from the internal register or internal cacheand decode them. During or after execution of the instructions,processor 910 may write one or more results (which may be intermediateor final results) to the internal register or internal cache. Processor910 may then write one or more of those results to memory 920. Inparticular embodiments, processor 910 executes only instructions in oneor more internal registers or internal caches or in memory 920 (asopposed to storage 930 or elsewhere) and operates only on data in one ormore internal registers or internal caches or in memory 920 (as opposedto storage 930 or elsewhere). One or more memory buses (which may eachinclude an address bus and a data bus) may couple processor 910 tomemory 920. Bus 960 may include one or more memory buses, as describedbelow. In particular embodiments, one or more memory management units(MMUs) reside between processor 910 and memory 920 and facilitateaccesses to memory 920 requested by processor 910. In particularembodiments, memory 920 includes random access memory (RAM). This RAMmay be volatile memory, where appropriate Where appropriate, this RAMmay be dynamic RAM (DRAM) or static RAM (SRAM). Moreover, whereappropriate, this RAM may be single-ported or multi-ported RAM. Thisdisclosure contemplates any suitable RAM. Memory 920 may include one ormore memories 920, where appropriate. Although this disclosure describesand illustrates particular memory, this disclosure contemplates anysuitable memory.

In particular embodiments, storage 930 includes mass storage for data orinstructions. As an example and not by way of limitation, storage 930may include a hard disk drive (HDD), a floppy disk drive, flash memory,an optical disc, a magneto-optical disc, magnetic tape, or a UniversalSerial Bus (USB) drive or a combination of two or more of these. Storage930 may include removable or non-removable (or fixed) media, whereappropriate. Storage 930 may be internal or external to computer system900, where appropriate. In particular embodiments, storage 930 isnon-volatile, solid-state memory. In particular embodiments, storage 930includes read-only memory (ROM). Where appropriate, this ROM may bemask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM),electrically erasable PROM (EEPROM), electrically alterable ROM (EAROM),or flash memory or a combination of two or more of these. Thisdisclosure contemplates mass storage 930 taking any suitable physicalform. Storage 930 may include one or more storage control unitsfacilitating communication between processor 910 and storage 930, whereappropriate. Where appropriate, storage 930 may include one or morestorages 930. Although this disclosure describes and illustratesparticular storage, this disclosure contemplates any suitable storage.

In particular embodiments, I/O interface 940 includes hardware,software, or both, providing one or more interfaces for communicationbetween computer system 900 and one or more I/O devices. Computer system900 may include one or more of these I/O devices, where appropriate. Oneor more of these I/O devices may enable communication between a personand computer system 900. As an example and not by way of limitation, anI/O device may include a keyboard, keypad, microphone, monitor, mouse,printer, scanner, speaker, still camera, stylus, tablet, touch screen,trackball, video camera, another suitable I/O device or a combination oftwo or more of these. An I/O device may include one or more sensors.This disclosure contemplates any suitable I/O devices and any suitableI/O interfaces 940 for them. Where appropriate, I/O interface 940 mayinclude one or more device or software drivers enabling processor 910 todrive one or more of these I/O devices. I/O interface 940 may includeone or more I/O interfaces 940, where appropriate. Although thisdisclosure describes and illustrates a particular I/O interface, thisdisclosure contemplates any suitable I/O interface.

In particular embodiments, communication interface 950 includeshardware, software, or both providing one or more interfaces forcommunication (such as, for example, packet-based communication) betweencomputer system 900 and one or more other computer systems 900 or one ormore networks. As an example and not by way of limitation, communicationinterface 950 may include a network interface controller (NIC) ornetwork adapter for communicating with an Ethernet or other wire-basednetwork or a wireless NIC (WNIC) or wireless adapter for communicatingwith a wireless network, such as a WI-FI network. This disclosurecontemplates any suitable network and any suitable communicationinterface 950 for it. As an example and not by way of limitation,computer system 900 may communicate with an ad hoc network, a personalarea network (PAN), a local area network (LAN), a wide area network(WAN), a metropolitan area network (MAN), or one or more portions of theInternet or a combination of two or more of these. One or more portionsof one or more of these networks may be wired or wireless. As anexample, computer system 900 may communicate with a wireless PAN (WPAN)(such as, for example, a BLUETOOTH WPAN), a WI-FI network, a WI-MAXnetwork, a cellular telephone network (such as, for example, a GlobalSystem for Mobile Communications (GSM) network), or other suitablewireless network or a combination of two or more of these. Computersystem 900 may include any suitable communication interface 950 for anyof these networks, where appropriate. Communication interface 950 mayinclude one or more communication interfaces 910, where appropriate.Although this disclosure describes and illustrates a particularcommunication interface, this disclosure contemplates any suitablecommunication interface.

In particular embodiments, bus 960 includes hardware, software, or bothcoupling components of computer system 900 to each other. As an exampleand not by way of limitation, bus 960 may include an AcceleratedGraphics Port (AGP) or other graphics bus, an Enhanced Industry StandardArchitecture (EISA) bus, a front-side bus (FSB), a HYPERTRANSPORT (HT)interconnect, an Industry Standard Architecture (ISA) bus, an INFINIBANDinterconnect, a low-pin-count (LPC) bus, a memory bus, a Micro ChannelArchitecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, aPCI-Express (PCIe) bus, a serial advanced technology attachment (SATA)bus, a Video Electronics Standards Association local (VLB) bus, oranother suitable bus or a combination of two or more of these. Bus 960may include one or more buses 712, where appropriate. Although thisdisclosure describes and illustrates a particular bus, this disclosurecontemplates any suitable bus or interconnect.

The components of computer system 900 may be integrated or separated. Insome embodiments, components of computer system 900 may each be housedwithin a single chassis. The operations of computer system 900 may beperformed by more, fewer, or other components. Additionally, operationsof computer system 900 may be performed using any suitable logic thatmay include software, hardware, other logic, or any suitable combinationof the preceding.

Herein, a computer-readable non-transitory storage medium or media mayinclude one or more semiconductor-based or other integrated circuits(ICs) (such, as for example, field-programmable gate arrays (FPGAs) orapplication-specific ICs (ASICs)), hard disk drives (HDDs), hybrid harddrives (HHDs), optical discs, optical disc drives (ODDs),magneto-optical discs, magneto-optical drives, floppy diskettes, floppydisk drives (FDDs), magnetic tapes, solid-state drives (SSDs),RAM-drives, SECURE DIGITAL cards or drives, any other suitablecomputer-readable non-transitory storage media, or any suitablecombination of two or more of these, where appropriate. Acomputer-readable non-transitory storage medium may be volatile,non-volatile, or a combination of volatile and non-volatile, whereappropriate.

Herein, “or” is inclusive and not exclusive, unless expressly indicatedotherwise or indicated otherwise by context. Therefore, herein, “A or B”means “A, B, or both,” unless expressly indicated otherwise or indicatedotherwise by context. Moreover, “and” is both joint and several, unlessexpressly indicated otherwise or indicated otherwise by context.Therefore, herein, “A and B” means “A and B, jointly or severally,”unless expressly indicated otherwise or indicated otherwise by context.

The scope of this disclosure encompasses all changes, substitutions,variations, alterations, and modifications to the example embodimentsdescribed or illustrated herein that a person having ordinary skill inthe art would comprehend. The scope of this disclosure is not limited tothe example embodiments described or illustrated herein. Moreover,although this disclosure describes and illustrates respectiveembodiments herein as including particular components, elements,functions, operations, or steps, any of these embodiments may includeany combination or permutation of any of the components, elements,functions, operations, or steps described or illustrated anywhere hereinthat a person having ordinary skill in the art would comprehend.Furthermore, reference in the appended claims to an apparatus or systemor a component of an apparatus or system being adapted to, arranged to,capable of, configured to, enabled to, operable to, or operative toperform a particular function encompasses that apparatus, system,component, whether or not it or that particular function is activated,turned on, or unlocked, as long as that apparatus, system, or componentis so adapted, arranged, capable, configured, enabled, operable, oroperative.

What is claimed is:
 1. A method of capturing an aerial vehicle, themethod comprising: rotating a first blade of the aerial vehicle, thefirst blade coupled to a first rotor of the aerial vehicle, wherein: thefirst blade has a contour configured to facilitate entanglement of apayload line of a winch system around a hub of the aerial vehicle; thecontour comprising at least one feature positioned along a distal end ofthe first blade, the feature being configured to hook the payload line;the first rotor is positioned coaxial to a second rotor of the aerialvehicle; counter-rotating a second blade of the aerial vehicle, thesecond blade coupled to the second rotor that is coaxial to the firstrotor; contacting, by a leading edge of the first blade, the payloadline of the winch system; pulling the payload line towards the hub ofthe aerial vehicle, wherein the payload line is pulled towards the hubas the first blade continues to rotate; and wherein continued rotationof the first blade and continued counter-rotation of the second bladecauses the payload line to be tangled around the hub of the aerialvehicle at a location on the hub that is between the first rotor and thesecond rotor.
 2. The method of claim 1, wherein the first blade of theaerial vehicle is a fixed-pitch blade.
 3. The method of claim 1, whereinthe payload line is pulled across a trailing edge of the first bladetowards the hub.
 4. The method of claim 1, wherein entanglement occursafter a pulling-in force on the payload line exceeds a tension force onthe payload line.